牛津上海版七年级英语上册Unit 3 句型、语法知识点讲解.docx

牛津上海版七年级英语下册Unit 3 句型、语法知识点讲解 本节内容： 重要句型及语法： 1. How long have you been a teacher? I have been a teacher for quite a few years. I have been a teacher since quite a few years ago. 语法链接：现在完成时的未完成用法 指的是动作开始于过去某一时刻，一直延续到现在，或可能还要继续下去。这里的动词要用持续性动词。常与for（+时间段）,since（+时间点）连用. 例如： He has lived here since 1978. 自从1978年以来，他一直住在这儿。（动作起始于1978年，一直住到现在，可能还要继续住下去。） I have been in the army for more than 5 years.我在部队已经呆了五年多了。（动作开始于5年前，一直延续至今，有可能还要继续下去。） for 和since for + 一段时间（for a week, for many years, for a long time等等）：（ prep. 达（时间段）之久；） Eg. I have been here for 5 weeks. He’s studied English for 3 years since + （表示过去某一时间的）时间点： （prep. conj. 自从（过去时间点）以来） （since +单词） （since+词组） （since+从句（一般过去时） Eg. I have been here since 2000. I have been here since 5 years ago. I have been here since I graduated in 2000. 对for或since引导的时间状语提问 必须用how long, 决不能用when. 例： I have lived here for 10 years. How long have you lived here? She has stood here since 2 hour ago. How long has she stood here? 含有For 和since时间状语的现在完成时和过去时的互相转换： 1. My uncle has been in the Army for 3 years. = (My uncle joined the Army 3 years ago.) 2. Peter has worked in this company since 2005. = (Peter started to work in this company in 2005.) = (Peter has worked in this company for 4 years.) 3. I have had the digital camera for 2 years. = I bought the digital camera 2 years ago. 2）但是有些短暂性动词不能和表示一段时间的状语连用。 如： He has left. 他离开了。 表示他不在这里， 在过去某个时候走的。 不能用 He has left for 3 days. 我们可以用 He has been away for 3 days. 他走了3天了。 常见非延续性动词和延续性动词转化形式： ①、用相应的延续性动词或者近义词；　　buy ------ have, borrow ----- keep, put on ------ wear, catch/get a cold ------ have a cold, come/go/become ------ be. ②、转换成 be＋名词;join the Party ------ be a Party member,join the army ------ be a soldier,go to school ------ be a student. ③、转换成be + 介词短语 :go to school ------ be in school,join the army ------ be in the army. ④、转换成be + adj./adv. :die ------ be dead, open——be open, get marr